1 1 


4  7.  3  '.  ^4 


Bulletin  No.  44 


U.  S.  DEPARTMENT  OF  AGRICULTURE 

DIVISION  OF  CHEMISTRY 


J  z 


S  W EET  C  A  S S  A Y  A 


ITS  CULTDRE,  PROPERTIES,  AN 


HARVEY     W.    WILE 
Chemist  of  the  I      S    Department  of  Acricult 


[SHEBB?   AUTHORITY    01    CB  i.vi:\    .,F    v.  ,  i:  I.  I  i.TVKfc-  . 


VV  A  BHING TON 

■  I  1  .\  I    PI 


Bulletin  No.  44 


U.  S.  DEPARTMENT  OF  AGRICULTURE 

DIVISION  OF  CHEMISTRY 


SWEET   CASSAVA: 


ITS  CULTURE,  PROPERTIES,  AND  USES 


BY 


HARVEY    W.    WILEY 
Chemist  of  the  U.  8.  Department  of  Agriculture 


PUBLISHED  BY  AUTHORITY  OF    I  ll  r  SK<  i.T.  I  AKV  of  AUKICULTUR] 


WASH!  N<i  TO  N 

(i  < )  V  B  B  N  M  K.NT    PRINTING    OFFIC1  i 

L894 


LETTER  OF  TRANSMITTAL. 


U.  S.  Department  of  Agriculture, 

Division  of  Chemistry, 
Washington,  D.  C,  September  lSt  1S94. 
Sii::  1  beg  to  submit  for  your  inspection  and  approval  the  manuscript  of  Bulletin 
No.  II.  giving  a  description  of  our  investigations  of  the  agricultural  possibilities 
of  >\\  eel  <;i-sa\  a. 
Respectfully, 

H.  W.  Wn.i  v. 
Chief  of  Division. 
Hon.  Charles  \V.  Dabxey,  Jr., 

Acting  Secretary  of  Agriculture. 


CONTENTS. 


Page 

Distribution — names — varieties 3 

<  assava  as  an  article  of  food 1 

Analysis  of  cassava  roots,  exclusive  of  bark I 

Analysis  of  cassava  Hour 5 

Extracts  from  correspondence 6-8 

Analysis  <>f  root  and  bark,  each  separa bely 9 

<  omparison  of  cassava  starch  with  Indian  coin  standi 10 

( 'oi nnos it  ion  of  the  ash   1- 

Methods  of  culture 13 

Conclusions i<» 

9 


SWEET  CASSAVA:  ITS  CULTURE,  PROPERTIES,  AND  USES. 


DISTRIBUTION — NAMES — VARIETIES. 

In  the  southern  peninsula  of  Florida,  and  growing  up  well  into  the 
frost  belt,  is  found  in  many  localities  a  cultivated  plant  known  as 
cassava,  or  sweet  cassava.  From  a  careful  study  of  the  climatic  con- 
ditions under  which  the  plant  flourishes  it  is  safe  to  assume  that  it  may 
also  be  grown  with  success  in  southern  Alabama,  Mississippi,  Louisiana, 
and  Texas.  Cassava'  is  a  name  which  should  properly  apply  ouly  to  the 
purified  starch  derived  from  the  roots  of  the  plant,  but  it  has  passed 
into  general  use  to  designate  the  plant  itself.  Botanically,  the  plant,  is 
known  as  Janipha  muni  hot,  Manihot  utili8sima)  Jatropha  manihot,  Man- 
ihot <iipi,  Manihot  Iceflingii,  and  Manihot  palmata.  One  of  its  common 
mimes  is  manioc  plant.  The  fleshy  root  of  this  plant  yields  the  greatest 
portion  of  the  daily  food  of  the  natives  of  many  portions  of  tropical 
America,  and  one  of  its  forms  of  starch  is  imported  largely  into  this 
country  as  tapioca.  It  is  a  woody  or  shrubby  plant,  growing  from 
fleshy,  tuberous  roots,  the  stems  being  smooth,  with  nodules  where  the 
leaves  grow. 

There  is  properly  only  one  variety  of  the  plant  growing  in  Florida, 
while  that. variety  which  grows  in  the  tropics  contains  so  much  hydro- 
cyanic acid  as  to  render  it  poisonous.  The  variety  grown  in  the  sub- 
tropical region  of  Florida,  however, contains  only  a  small  quantity  of 
hydrocyanic  acid,  and  is  therefore  commonly  known  as  sweet  cassava. 
Some  of  tin- growers  of  the  plant  in  Florida  claim  that  t  wo  varieties 
grow  in  the  State,  one  of  which  is  poisonous  on  account  of  the  large 
amount  of  hydrocyanic  acid  which  it  contains,  and  the  other  oonpoison- 
ous,  containing  only  a  little  hydrocyanic  acid.  It  is  quite  probable, 
however,  that  alter  the  poisonous  variety  has  grown  lor  a  long  while 
in  a  subtropical  climate  it  would  lose  hugely  its  poisonous  properties. 
The  leaves  of  the  poisonous  variety  in  the  tropics  usually  have  seven 
branches  palmately  divided.   The  leaves  of  the  .s\\  ret  variety  are  usually 

only  five-parted.  Tin'  botanists  clearly  recognize  two  distinct  varieties. 
For  instance,  in  the  ••Treasury  <>!'  Hot  an\  ."'  page  7  IS,  the  following 
remarks  are  made: 

it  is  quite  clear  thai  while  the  root  of  one  ia  bitter  and  a  virulent  ]><»ix»ii  that  of 
the  other  1-  sweet  and  wholesome,  and  is  commonly  eaten  cooked  as  a  vegetable. 
Both  of  them,  especially  the  bitter,  are  most  extensively  cultivated  over  the  greater 


part  of  tropical  America  and  yield  an  abundance  of  "wholesome  and  nutritious  food 
the  poison  of  the  bitter  kind  being  got  rid  of  during  the  process  of  preparation  it 
undergoes.  The  poisonous,  expressed  juice,  if  allowed  to  settle,  deposits  a  large 
quantity  of  starch  known  as  Brazilian  arrowroot  or  tapioca  meal,  from  Which  the 
tapioca  of  the  shops  is  prepared  by  simply  torrefying  the  moist  starch  upon  hot 
plates,  the  heat  causing  the  starch  grains  to  swell  and  burst  and  become  agglutinated 
together.  A  sauce  called  cassareep,  used  for  flavoring  soups  and  other  dishes,  partic- 
ularly the  West  Indian  dish  known  as  pepper  pot,  is  also  prepared  from  this  juice  by 
concentrating  and  rendering  it  harmless  by  boiling.  Another  of  the  products  of 
cassava  is  an  intoxicating  beverage  called  piuiarrie,  but  the  manner  of  preparing  it 
is  not  calculated  to  render  it  tempting  to  Europeans.  It  is  made  by  the  women  who 
chew  cassava  cakes  and  throw  the  masticated  materials  into  a  wooden  bowl,  where 
it  is  allowed  to  ferment  for  some  days,  and  then  boiled.  It  is  said  to  have  an  agree- 
able taste. 

CASSAVA  AS  \N  ARTICLE  OF  FOOD. 

The  attention  of  the  Division  of  Chemistry  was  first  called  to  the 
cassava  plant  as  an  article  of  food  and  a  possible  source  of  starch,  in 
1888,  in  a  letter  received  from  Mr.  R.  H.  Burr,  of  Bartow,  Fla.  Mr. 
I  iu  11*  also  sent  a  package  of  cassava  roots.  He  described  the  plant 
and  its  uses  in  the  following  words: 

The  roots  do  not  last  long  after  digging,  drying  np,  or  rotting.  Since  this  variety 
of  cassava  is  not  the  bitter  or  poisonous  kind,  it  is  generally  known  in  Florida  as 
the  sweet  cassava.  The  roots  are  fed  to  all  kinds  of  stock  in  a  fresh  state,  and  are 
greatly  relished.  It  has  been  sufficiently  tested  here  to  show  its  great  value  as  a 
stock  food.  The  yield  under  favorable  conditions  is  astonishing.  I  have  recently 
dug  one  plant  of  one  year's  growth  which  weighed  50  pounds,  being  at  the  rate  of 
more  than  1.500  bushels  to  the  acie.  Eight  hundred  to  1,000  bushels  per  acre  can  be 
confidently  reckoned  on. 

The  roots  received  by  us  were  long  and  slender  and  of  various  sizes; 
some  of  them  were  quite  2  feet  long,  and  weighed  several  pounds.  The 
analysis  of  the  sample,  exclusive  of  the  bark,  calculated  t<>  dry  sub- 
stance, is  given  in  the  following  table: 

Serial  Dumber 6547 

Ash per  cent . .       1.94 

Oil  (petroleum  ethei  extract) do.. ..     L 27 

Ether  extracl  I  resins,  alkaloids,  organic  acids,  etc.  | <1<» 71 

Alcohol  extracl  (amids,  sugars,  glncosids,  etc.)  <1<> —   17.43 

('rude  fiber do....     L08 

Starch do. ...  71.86 

Albuminoids  (calculated  from  nitrogen) do..  .     :>.  IT 

L00.  7:: 

In  regard  to  the  method  of  analysis  little  need  i»e  s;ii<l ;  it  was  carried 
on  in  accordance  with  the  well  -established  rules  of  plant  analysis,  aa 
laid  down  by  Dragendorff.    The   first  extraction  of  petroleum  ether 

gave  the  tat  or  oil  alone,  and  the  BUfosequeill  extract  inn  with  sulphuric 

ether  gave  the  resins,  alkaloids,  and  organic  acids,  That  portion  of 
nitrogen  existing  as  amids  was  estimated  in  the  alcoholic  extract. 
The  total  nitrogen  iraa  also  estimated  and  entered  aa  albuminoids;  a 


small  portion  of  the  nitrogen  has  thus  been  counted  twice  in  the  total 
results,  which  add  up  a  little  over  100.  A  characteristic  feature  of  the 
cassava  root  is  shown  in  the  large  amount  of  substance  present,  solu- 
ble in  alcohol.  The  amount  of  starch  also  compares  fairly  well  with 
the  best  varieties  of  potatoes.  On  account  of  the  large  quantity  of 
sugars  present,  the  cassava  root  could  be  more  economically  used  for 
the  manufacture  of  glucose  than  for  starch.  There  is  no  doubt,  how- 
ever, of  the  fact  that  a  fine  article  of  starch  for  the  laundry  or  for  food 
can  be  made  from  the  cassava  root  growing  in  this  country. 

In  addition  to  the  fresh  root  above  noted,  two  samples  of  the  dried 
root  or  cassava  meal  have  also  been  examined.  Xo.  5922  was  sent  to 
us,  described  as  pulverized  manihot  root  or  cassava  flour.  The  root  is 
first  peeled,  chopped  into  thin  slices,  dried  in  the  sun  two  days,  and 
pulverized.  It  was  prepared  by  Prof.  W.  II.  Kern,  of  Bartow,  Fla. 
No.  5023  was  labeled  pulverized  cassava,  with  the  starch,  or  a  portion 
of  it,  and  glucose  washed  out,  the  remaining  pulp  dried  in  the  sun; 
prepared  by  Prof.  Kern. 

Prof.  Kern  sent  a  letter  with  the  samples,  from  which  the  following 
extracts  are  made: 

Allow  me  to  say  that,  owing  to  the  prodigious  yield  per  acre  of  what  we  here  know 
as  cassava  and  its  alleged  value  as  a  feed  and  food  plant  and  for  its  yield  of  starch  and 
glucose,  it  is  attracting  a  very  great  deal  of  attention  here  now.  The  plant  here  grown 
is  different  from  the  manioc  root  of  South  and  Central  America;  our  root  contains 
no  poisonous  elements  which  need  to  he  dissipated  by  heat.  It  is  customary  here 
for  many  persons  to  make  their  own  starch  from  it.  The  root,  which  must  remain 
in  the  ground  until  one  is  ready  to  use  it,  is  dug.  washed,  and  its  two  inner  and 
outer  peelings  removed;  it  is  then  grated  and  the  pulp  washed,  the  water  poured 
ott  in  a  vessel  and  allowed  to  stand,  when  the  pure  Starch  -rttles  in  the  bottom.  The 
clear  water  is  again  drawn  off  and  the  starch  allowed  to  dry.  The  palp,  after 
having  the  starch  washed  out,  may  he  used  at  once  in  making  puddings  by  the 
addition  of  milk,  eggs,  etc.  This  washed  pulp  may  he  sun-dried  and  thus  kept, 
forming  valuable  meal  or  Hour,  from  which  nice  bread  may  he  made.  Necessitated 
as  we  are  in  south  Florida  to  buy  all  our  wheat  Hour,  anything  which  acts  as  a  suh- 
stitute,  either  in  whole  or  in  part,  is  of  great  value  to  us. 

The  analyses  of  two  samples  of  flour  arc  given  in  the  following 
table: 

Serial  number 5922  5923 

Water per  cent..  10.56  11.  8G 

Aah do.*...  1.86  1.13 

Oil  and  fat do....  1.50 

Resins,  alkaloids,  and  organic  acids do .til  .43 

Amids,  sugars,  glucosids do 13.69  1.  50 

Dextrin,  gum,  etc.,  by  difference do 2  85  5.63 

Crude  fiber  do 2.96  1.15 

Nitrogenous  bodies do 1.31  1.31 

Starch do....  64.63  70.13 

From  the  above  analyses  it  is  seen  thai  the  cassava  can  never  take 
the  place  of  the  flour  made  from  cereals  ns  a  food  material  on  account 
of  the  small  portion  of  nitrogenous  matter  which  it  contains.     It  seems 


to  me,  however,  that  it  miglit  very  well  take  the  place  of  potatoes,  and 
its  value  as  a  food  should  not  be  underestimated. 

Id  order  to  get  further  information  in  regard  to  the  growth  and  uses 
of  cassava  in  Florida,  a  circular  was  sent  to  as  many  addresses  as  could 
be  obtained  of  persons  interested  in  its  growth  in  that  part  of  the  State 
suited  to  its  culture.  This  circular  asked  for  information  in  regard  to 
the  time  and  method  of  planting,  method  of  cultivation,  kind  of  soil 
and  fertilizers,  proper  time  for  harvesting,  length  of  time  the  roots  can 
remain  in  the  ground,  the  effect  of  frost  on  the  plant,  the  yield  of  roots 
per  acre,  their  value  as  food,  method  of  preparing  for  food  and  starch, 
profit  of  cultivating,  and  the  certainty  of  the  crop.  In  all,  about  three 
hundred  answers  were  received  to  these  questions.  Some  of  these 
answers  stated  that  the  crop  was  not  grown  in  the  part  of  the  State 
from  which  they  were  written.  A  few  of  the  replies  were  unfavorable 
in  regard  to  the  utility  and  value  of  the  crop.  Nearly  all  of  them, 
however,  represented  that  the  crop  was  a  certain  one,  extremely  valu- 
able, and  the  roots  an  excellent  food  for  man  and  beast. 

Many  of  the  correspondents  give  rather  full  notes  in  regard  to  the 
value  of  the  crop  and  the  localities  in  which  it  grows.  In  Florida  it 
seems  to  flourish  in  almost  every  part  of  the  State. 

Mr.  J.  B.  Pixton,  of  Ellerslie,  Pasco  County,  writes: 

I  found  it  growing  profusely  in  Taylor  County,  this  State,  sonic  ydars  since.  The 
roots  were  thicker  than  a  man's  arm  and  about  4  feet  Ion;;.  The  settlers  almost  live 
on  it. 

Taylor  County  is  in  the  northwestern  part  of  the  State,  bordering  on 
the  Gulf.  The  same  w Titer  says  that  in  his  locality  it  did  not  do  so  well 
and  that  he  could  make  nothing  of  it. 

Prentice  Bailey,  in  an  article  in  the  Tropical  Sun  of  February  9,1803, 
published  in  Juno,  Dade  County,  says: 

I  consider  it  superior  to  any  root  crop  grown  in  this  country.  It  is  \ cry  produc- 
tive; it  has  ;i  remarkable  immunity  from  drought,  flood,  and  disease;  it  is  easy  to 
harvest,  easy  of  cultivation,  and  occupies  tin-  ground  during  the  whole  growing 
season  to  tlie  exclusion  of  noxious  plants.  The  pork  made  from  feeding  it  is  solid 
and  delicate  as  chicken,  and  t  he  lard  is  as  firm  as  thai  of  corn-fed  hogs.  It  produces 
a  good  How  of  rich  milk  and  a  firm,  golden  butter,  from  l  acre  of  cassava  enough 
r<»oi-  may  be  obtained  to  fa1  ten  L0  hogs  or  feed  3  milch  cows  during  t he  entire  year. 

.Mr.  Bailey  states  thai  in  his  opinion  it  can  be  grown  as  far  north  as 
Atlanta,  Ga.,  in  w  liicli  opinion,  however.  1  am  unable  to  concur,  as  pre- 
ponderating testimony  goes  to  show  thai  the  plant  will  not  <lo  well  in 
localities  subject  to  heavy  frosts. 

Mr.  Fred  W.  [nman,  of  Winter  Haven,  Polk  County,  says: 
There  is  do  better  food  for  stock,  especially  during  the  winter  months.     1  have  fed 

m>    cows,  mules,  horses,  hogs,  and  poultry    upon  h  ever;   season   for  the  pasl  Bis 
It  fattens  better  than  corn.    There  is  nothing  grown  in  this  country   thai 

oan  compare  with  it.     It  has  no  enemj  but  frost,     I  esteem  this  crop  one  of  the  mosl 

essential  as  well  as  profitable  thatthe  Florida  farmer  oan  grow,     [t  furnishes  food 

for  my  stock,  poultry,  etc.,  for  about  Dine  months  in  the  year. 


Mr.  Sherman  Adams,  in  the  Florida  Agriculturist,  says: 

Soil  suitable  for  corn  is  appropriate  for  cassava.  It  must  not,  however,  be  wet 
land  or  land  subject  to  overflow,  as  that  will  rot  the  tubers.  Frost,  if  severe,  will 
kill  the  plant  so  effectually  that  but  a  small  proportion  will  sprout  again.  By  sav- 
ing the  stumps  when  the  roots  are  dug,  and  planting  them,  they  will  sprout  and 
grow,  though  the  tops  be  killed  two  or  three  times.  There  are  about  2,740  hills  per 
acre.  On  land  that  will  not  grow  more  than  5  bushels  of  corn  per  acre,  cassava 
will  average  from  3  to  5  pounds  per  hill,  or,  at  a  very  moderate  estimate,  4  to  5 
tons  per  acre. 

Mr.  S.  W.  Carson,  of  Midland,  Polk  County,  Bays: 

There  is  but  one  variety  of  cassava,  viz,  the  sweet  kind,  grown  in  Florida.  I  have 
never  seen  any  sample  of  the  bitter  variety.  A  Spaniard  who  was  once  conversing 
with  me  on  the  subject  of  cassava  gave  his  idea  as  a  proper  definition  of  cassava 
as  "the  life  of  man."  After  cultivating  the  plant  for  a  quarter  of  a  century,  I  am 
ready  to  agree  with  him.  If  judiciously  used  it  will  reduce  the  grain  rations  for 
horses  and  mules  at  least  one-half.  For  cows  you  may  keep  bits  of  it  mixed  in  the 
slops  and  other  food.  I  have  never  cooked  it  for  stock,  as  I  believe  it  is  best  fed  raw. 
In  feeding  to  fowls,  it  should  be  thrown  into  the  yard  in  its  raw  state  daily,  but  in 
small  quantities.  After  feeding  on  it  for  one  month  any  fowl  will  be  fat  enough  to 
cook  without  lard  or  butter.  Honeybees  forage  largely  on  the  blooms;  cattle  eat 
with  relish  the  tender  shoots.  The  finest  fowl  yard  imaginable  could  be  made  in  a 
cassava  patch  by  turning  the  fowls  into  the  patch  ten  months  after  planting.  The 
roots  would  supply  them  with  food  and  the  tops  shelter  them  from  the  sun. 

1  regard  the  rolling  pine  lands,  containing  some  willow  oak,  to  lie  the  best  for 
cassava,  and  the  southern  counties  to  be  best  suited  to  it.  Let  the  soil  be  well  pre- 
pared by  plowing  and  harrowing,  rows  checked  about  1  feet  apart,  and  one  piece  laid 
in  each  hill.  I  think  they  should  never  be  closer  together  than  1  feet,  and  .">  would 
be  better.  Cassava  has  been  known  to  grow  for  three  years  in  this  country.  It  will 
continue  to  grow  until  the  cold  kills  it;  then,  by  breaking  off  the  stems  when  they 
are  red,  the  stubble  will  sprout  up  in  the  spring.  As  to  the  seeds  of  the  cassava, 
they  will  ripen  in  about  one  year.  If  puddings,  custards,  etc.,  are  desired,  the  roots 
must  be  peeled  and  grated;  salt,  sugar,  etc..  may  be  used  according  to  taste.  The 
Spaniards  make  bread  of  it  simply  by  grating  the  root,  and  adding  salt  and  a  little 
soda.  Now,  there  is  no  doubt  in  my  mind  but  that  30  tons  of  cassava  root  per  acre 
can  be  produced.  When  I  think  of  the  tapioca,  glucose,  and  starch  there  are  in  it, 
and  how  abundantly  it  can  be  turned  into  bacon  and  lard,  milk  and  butter,  mutton 
and  beef.  I  feel  confident  that    it  will  pay  better  than  any  other  plant  in  the  world. 

Mr.  Paul  Dupuy,  of  Boardman,  Marion  County,  says  but  little  cassava 

is  growl]  in  that  locality: 

Some   months   ago  I  spent    fourteen   months    in   Brazil,  where  the   mandioc  plant  is 

generally  used  as  food  by  man  and  beast.  En  truth,  it  constitutes  the  bread  of  the 
country,  being  a  general  article  of  food  for  all  classes.  [\  is  prepared  for  food  in 
Brazil  by  grating  it  into  a  coarse  pulp  and  pressing  it  to  gel  rid  of  as  much  of  the 
juice  as  possible,  which  contains  a  large  proportion  of  hydrocyanic  acid.  The  pulp 
is  then  placed  in  Bhallow  copper  pans  and  thoroughly  dried  oyer  a  gentle  lire.  In 
this  condition  it  re-.eini.les  com  grits,  and  it  is  eaten  in  this  Bhape,  or  it  can  be 
cooked  and  prepared  as  corn  meal  and  other  starchy  product-.  The  sediment  from 
the  expressed  juice,  when  dried,  constitutes  the  tapioca  ol  commerce.  A.s  a  starch 
product  1  do  not  think  it  can  be  excelled,  because  of  its  enormous  product  per  acre. 

Mr.  A.  Stephens  Means,  of  Johns  Pass,  Qillsboro  County,  says: 

It  has  great  value  as  stock   food,  being  very  rich  in  starch,  and  most   animals  eat 

it  greedily.      It  is  a  nourishing  food  for  man  and  can  lie  used    m    B   number   of 

il>stitute  for  potatoes,  or  the  start  h  niav  bo   extracted    and    used  tor  puddings, 

etc.    An\  soil  suitable  for  potatoes  can  boused  for  cassava. 


Mr.  M.  K.  Lyman,  of  Lantana,  Dade  County,  writes: 

I  have  no  success  with  cassava.  I  have  made  several  efforts  to  raise  the  plant  and 
have  failed  in  every  case.  I  have  splendid  success  with  tanyah,  or  taro.  It  makes 
a  Bnbstitnte  for  the  potato  all  the  year,  being  an  evergreen,  yielding  edible  roots  the 
year  around. 

Mr.  William  Fisher,  of  Clay  County,  says: 

1  doubt  very  much  if  cassava  ever  supplants  the  sweet  potato  as  human  food,  for  the 
Southerners  like  the  sweetness  of  the  potato  and  it  can  be  cooked  in  one-third  the 
time  required  for  cassava.  But  as  stock  feed  I  believe  the  cassava  is  well  worth  a 
trial.  In  my  judgment,  the  planting,  cultivation,  and  harvesting  of  it  would  involve 
il>or  than  the  potato;  the  seed  is  as  easily  wintered;  the  nop  can  be  left  in  the 
ground  all  winter,  and  it  yields  more  per  acre  than  the  potato  and  is  apparently 
equal  to  it  in  nutritive  value. 

.Mr.  Stephen  Powers,  editor  of  the  Florida  Dispatch,  says: 

I  he  plant  is  indigenous  to  the  West  Indies  and  to  Africa.  In  the  West  Indies  it 
is  known  as  cassava,  while  in  South  America  it  is  commonly  known  as  mandioca,  or 
manioca.  The  name  yucca,  which  some  people  insist  on  giving  it,  is  a  clear  mis- 
nomer, since  the  yucca  belongs  to  the  Liliacca,  or  lily  family,  while  the  cassava 
belongs  to  the  Euphorbiaceas  family.  The  plant  was  eaten  by  the  South  American 
and  Caribbean  Indians  centuries  before  this  hemisphere  was  discovered  by  Euro- 
peanB.  Southey  says  of  it :  "If  Ceres  deserved  a  place  in  the  mythology  of  Greece, 
far  more  might  the  deification  of  that  person  have  been  expected  who  instructed  his 
fellows  in  the  use  of  mandioca. "  In  Brazil,  in  the  form  of  coarse  flour,  a  majority 
of  the  population  use  it  the  year  round  in  lieu  of  bread.  A  mild  intoxicant  is  also 
distilled  from  it  which  is  the  universal  drink  of  the  lower  classes.  The  South 
American  Indians  use  the  following  formula  for  manufacturing  cassava  beer:  The 
roots  are  sliced,  boiled  till  soft,  and  cooled.  They  are  then  chewed  mouthful  by  mouth- 
ful, the  masticated  cuds  being  returned  to  the  vessel.  [Thisprocess,  although  not  so 
stated  in  the  description,  is  evidently  intended  to  transform  the  starch  into  sugar 
by  the  act?on  of  the  saliva.]  The  jar  is  then  filled  with  water  and  boiled  for  several 
honrs  with  constant  stirring.  The  liquid  is  then  poured  off  into  another  jar,  half 
buried  in. the  dirt  floor  of  the  hut  in  which  the  family  lives,  closely  covered,  and 
allowed  to  ferment  two  or  three  days.  When  required  for  use  a.  lire  is  built  around 
it.  and  the  beverage  is  served  steaming  hot.  It  is  not  as  palatable  for  human  fool 
as  Bweetfpotatoes,  and  to  expect  therefore  to  substitute  cassava  for  either  the  sweet 
or  the  [rish  potato  would  be  a  step  from  a  higher  to  a  lower  civilization,  but  as  a 
food  fortlive  stock  it  has  a  great  superiority.     It  is  worth  at  least  25  per  cent  more 

than  sweet  potatoes   to    produce  milk  or   fat.      With  no  more  manure,  and  less  cult  i 
ration  than  is  required  for   Indian  corn,  it  will  produce  an   amount  of  feed  worth  at 
leasl  four  tune-,  as  much  for  fattening  animals  and  incomparably  more  for  producing 
milk.     It  is  easier  to splant  and  cultivate  than  sweet  potatoes,  but  harder  to  dig,  so 

it  may  he  called  even  on  this  store.  With  the  same  manuring  it  will  yield  GOO 
bushels  pel-  acre,   while  sweet   potatoes  will  yield  onl\    500, 

Mr.  J.  II.  Moore,  of  Keuka,  Fla..  in  a  letter  to  the  same  paper  of 
November  24,  L887,  describes  some  of  the  uses  of  cassava.  Prom  his 
letter  tin-  following  extract  is  made: 

Cut  the  stalks  about  l  inch  above  the  ground,  just  before  frost;  after  cutting,  the 

■talks  Should  be  left   to  dry  in  a  COOl  place  a  lew    weeks,  and  then  placed  in  :i  trench 

and  covered  until  t  line  for  planting,    Some  save  the  stalks  by  keeping  them  in  a  dry, 

COOl  place  until    I  "elu  uai  \    and  I  hen   planting.      The  roots  should  he  dug  M  used  ;  t  hey 

will  not  keep  in  good  condition  «>ni  of  the  ground  more  than  three  or  four  days,  it 
i-  perhaps  the  besl  feed  we  can  raise  for  hogs;  it  is  also  :i  ftne  iced  for  poultry.  We 
often  bake  it  Like  iweel  potatoes,  and  also  ulico  and  fry  it  like  Irish  potatoes. 


M.  Sacc  lias  addressed  a  letter  to  the  National  Society  of  Agriculture 
of  France  concerning  the  cassava,  which  he  calls  Manihot  utilissima. 
He  is  of  the  opinion  that  the  poisonous  varieties  are  different  botau- 
ically  from  the  innocent.  Manihot  is  the  bread  of  tropical  regions.  The 
innocent  variety  is  cultivated  in  Bolivia,  and  the  botanists  there  call  it 
Manihot  a'ipi.  The  plant  grows  from  1  to  2  meters  in  height,  witli 
straight  and  naked  stalks,  since  they  only  develop  leaves  at  their 
extremities;  the  only  care  given  to  them  in  their  cultivation  is  to  keep 
them  free  from  weeds.  The  roots,  to  the  number  of  five  to  nine,  are  of 
the  size  of  the  closed  hand.  The  following  analysis  of  the  roots  of  the 
Manihot  a'ipi  is  given: 

Ter  rent. 

Water 70.29 

Starch 14.40 

Sugar,  salts,  and  malic  acid 1.01 

Fibrin  and  yellow  coloring  matter 08 

Crude  fiber 3. 16 

Ash 10.82 

From  the  above  it  is  seen  that  the  roots  of  the  tropical  plant  are  quite 
different  from  those  produced  in  our  own  country.  In  regard  to  the 
distribution  of  the  two  varieties,  M.  Sacc  makes  the  following  observa- 
tion : 

In  Cuba  I  have  seen  only  the  poisonous  variety.  The  same  is  true  of  Brazil,  where 
I  have  not  seen  the  Manihot  a'ipi  except  in  the  Swiss  colony,  Porto  Real.  As  to  the 
product  of  the  two  varieties,  it  is  the  same;  the  stalks,  which  are  the  size  of  the 
finger,  are  from  1  to  2  meters  in  height.  I  have  not  been  able  to  analyze  the  Leaves 
of  this  interesting  vegetable,  but  as  they  are  much  sought  after  by  eattle  they  are 
probably  very  nutritious. 

These  interesting  facts  concerning  the  cassava  plant,  derived  from 
our  own  analyses  and  observations  and  from,  the  correspondence  noted 
above,  have  led  us  to  believe  that  a  wider  knowledge  of  the  properties 
of  this  interesting  plant  would  prove  of  interest  not  only  to  the  growers 
thereof,  but  also  to  capitalists  and  manufacturers,  who  might  be  inter- 
ested in  it  as  a  promising  source  of  food  and  as  the  raw  material  for 
the  manufacture  of  starch  and  glucose. 

A  large  quantity  of  the  root,  therefore,  was  obtained  from  Florida, 
the  bark  separated  from  the  root,  and  each  subjected  to  analysis  with 
the  following  results  : 


Peeled  root. 

Fiber 
after 

1  i  lim\  ;il 

"i  Btaroh, 

Hark  of  mot. 

Fresh. 

Dry. 

Fresh. 

Dry. 

Moist  imp 

IT 

64 

.M 

6  52 

• 

61.30 

Ki  her  extract  

41 
I  66 

HO  (if, 
■J  26 
1.31 

11  27 

. 80 

1. 03 

64.64 

1.42 

1  70 

Albuminoids  (nitrogen      8.35) 

Starch  (diastase  extracl  Inverted  vrithHCIj  

Filter 

- 

Ash 

Undetermined 

77    -'7 

100.  IK) 

100.  00 

100.00  .         100.00 

10 

With  the  starch  in  the  analysis  given  above  is  reckoned  also  the  solu- 
ble carbohydrates,  consisting  almost  exclusively  of  cane  sugar,  and  of 
which,  in  an  analysis- of  another  portion  of  the  dry  substance,  as  high 
as  17  per  cent  were  found.  In  the  laboratory  it  is  not  difficult  to  pre- 
pare crystallized  cane  sugar  from  the  aqueous  extract  of  the  fresh  pnlp. 
We  have  made  such  a  preparation.  The  percentage  of  sugar  in  the 
plant,  however,  is  too  low  to  excite  any  reasonable  hope  of  the  preparation 
of  this  article  on  a  commercial  scale.  The  most  promising  way  to  save 
it  is  byconversion  into  glucose,  as  indicated  in  another  place.  The 
undetermined  portion  consists  of  the  digestible  fiber  and  carbohydrates 
of  the  pentose  series.  The  pentosans  in  the  liber  were  determined  by 
the  furfurol  process,  as  modified  by  Krug,  and  the  amount  in  the  air. 
dried  material  was  found  to  be  3.92  per  cent,  and  in  the  material  after 
the  removal  of  the  starch  5.33  per  cent. 

The  fresh  root  was  found  to  contain  .°>S.7  per  cent  of  dry  matter,  being 
considerably  more  than  was  found  in  the  fresh  sample  of  the  previous 
analysis.  Of  this  38.7  per  cent,  30. OS  consisted  of  starch  and  soluble 
carbohydrates. 

Experiments  were  made  to  determine  the  yield  of  air-dry  starch  which 
could  be  obtained  from  the  roots  by  laboratory  work.  Two  sets. of 
experiments  were  made.  In  the  first  set  the  roots  were  pulped  on  a 
Pellel  rasp,  used  for  preparing  beet  pulp  for  instantaneous  diffusion. 
Twelve  kilos  of  the  impeded  root  were  rasped  in  this  way  and  the  starch 
separated  by  washing  through  a  sieve  of  bolting"  cloth.  The. washings 
and  settlings  were  collected  and  dried. in  the  ordinary  method  of  starch 
manufacture.  The  yield  of  pure  starch  was  3,105  grams,  equivalent  to 
25.9  per  cent  of  the  total  weight  of  the  root.  The  starch  was  almost 
absolutely  pure,  containing  only  a  trace  of  nitrogenous,  matter.  In  the 
second  experiment  10  kilos  of  the  root  were  ground  in  a  pulping  machine, 
used  for  preparing  green  fodder  for  analysis.  The  pulp  was  much  less 
line  than  that  produced  by  the  Pellel  rasp.  Treajed  in  the.  same  way, 
the  yield  of  air  dry  starch  was  2,&60  grams,  or  23.6  percent.  One  of  the 
Striking  points  in  connection  with  the  work  is  that  the  residue  from  the 
Starch, which  consisted  largely  of  liber,  as  will  be  seen  by  reference  to 
I  lie  above  analysis,  contained  stdl  a  large  percentage  of  starch,  show- 
ing thai  by  the  process  employed  the  whole  of  the  starch  was  not 
Secured  from  the  pnlp.  The  diameter  of  fche  Starch  granules  is  a  little 
over  0.01  mm.,  being  about  seven  times  smaller  than  the  average  of 
potato  starch. 

COMPARISON    <>!'   cassava    STA.R0B    AND    INDIAN  CORN    STARCH. 

The  illustrations  given  are  from  photomicrographs  of  the  starch 
granules,  \\  hich,  for  purposes  of  comparison)  are  accompanied  by  illus- 
trations of  the  finest  prepared  Indian  corn  starch. 

Fig.  1.  Plate  i,  shows  the  granules  of  cassava   starch  in  plain   light, 

magnified  160  diameters. 


11 

Fig.  2,  Plate  I.  shows  Indian-corn  starch  in  similar  conditions.  The 
average  size  of  the  particles  is  the  same  in  both  instances,  viz,  0.012mm- 
The  cassava  particles  are  more  irregular  in  size,  and  are,  moreover,  to 
be  distinguished  from  the  maize  particles  by  greater  evenness  of  out- 
line. The  cassava,  however,  more  nearly  resembles  the  maize  starch 
than  it  does  any  other  well-known  variety,  and  by  reason  of  this  resem- 
blance could  easily  take  the  place  of  maize  starch  in  the  kitchen  and 
laundry. 

Fig.  1,  Plate  n,  shows  cassava. starch  magnified  150  diameters  and 
viewed  by  polarized  light.  Only  the  larger  particles  are  well  in  focus, 
nevertheless  the  cross  can  be  seen  on  the  smaller  by  close  inspection. 

Fig.  2,  Plate  n,  shows  maize  starch  in  similar  conditions.  While  it 
would  be  difficult  in  all  cases  to  distinguish  these  two  starches  by  the 
microscope,  yet  there  are  some  points  of  difference,  as  have  already 
been  noted,  by  means  of  which  the  expert  may  usually  be  successful  in 
the  discrimination. 

The  cassava  which  grows  in  tropical  regions  contains  a  notable  per- 
centage of  hydrocyanic  acid,  so  great,  in  fact,  that  it  can  not  be  used 
directly  as  a  food.  The  so-called  poisonous  cassava  is  boiled,  to  expel 
the  hydrocyanic  acid  before  being  used  for  feeding  purposes.  A  care 
ful  determination  was  made  of  the  hydrocyanic  acid  in  the  fresh  root 
and  the  amount  was  found  to  be  in  considerable  quantity,  but  not  suf- 
ficiently large  to  be  alarming.  Nevertheless,  anj  possible  danger  could 
be  avoided  before  using  the  material  as  a  food  by  subjecting  it  to  a 
sufficient  heat  to  expel  the  hydrocyanic  acid.  The  hydrocyanic  acid 
seems  to  be  distributed  throughout  the  pulp,  and  particularly  in  the 
juices  which  can  be  expressed  from  the  pulp.  ^No  injurious  effect  from 
the  hydrocyanic  acid  has  ever  been  observed  in  the  case  of  animals  led 
on  cassava  in  Florida. 

The  bark  of  the  root  was  also  subjected  to  analysis,  as  will  be  seen 
by  reference  to  the  following  table.  It  contained  do  starch,  the  unde- 
termined matter  being  chiefly  digestible  liber  and  pentosans. 

The  mineral  matters  extracted  from  the  soil  are  distributed  as  indi- 
cated in  the  table.  The  amount  of  ash  in  the  root  itself  is  quite  low, 
showing  that  the  cassava  plant  does  not  require  a  soil  very  rich  in 
mineral  constituents.  The  amount  of  mineral  matter  taken  from  the 
Boil  by  100  kilos  of  the. fresh  root  is  approximately  ouly  half  a  kilo. 
The  albuminous  matters  are  also  present  in  small  quantities, being 
only  slightly  larger  in  weight  than  the  ash  Itself.  The  plant,  therefore, 
is  one  which  seems  particularly  suited  to  teed  almost  exclusively  from 
the  air  and  water,  and  hence  is  one  which  could  be  recommended  on 
the  sandy  soils  of  Florida  as  a  crop  which  would  require  the  minimum 
of  fertilization. 


12 


COMPOSITION    OF    THE    ASH. 


The  ash  of  the  peeled  root  and  the  bark  of  the  root  was  subjected  to 
analysis,  with  the  following  results: 

Analysis  of  the  ash  of  cassava  root. 


Constituents. 

Peeled  root. 

Bark  of  root. 

A. 

]•>  r  et. 
0.30 
0.97 
7.  IS 
n.  M 
10.63 
7  36 
1.  12 
41.72 
15.58 
3.  67 

B. 

Mian. 

A 

B. 

Mean. 

Carbon  

Per  ct. 
0.31 
0.91 
7  15 

0.66 
10.64 

7. 3:. 

1   28 
41.54 

15.59 

• 

Per  ct. 

0.31 

0.94 

7.  15 

0.  tin 

10.  04 

7.  35 

1.20 

41.  63 

15.  58 

3.  73 

9.14 

2.  75 

Per  ct. 
0.79 
10.53 

52.  99 
2.46 

3.31 
0.84 
14.73 

•_'.  44 
1.71 

1.41 

Per  ct. 

n.77 

11.36 

52.  16 

2.  44 

6.65 

3.33 

L.05 

14  68 

2. 4t; 

1.71 
2.50 
1.42 

Per  ct. 

n 

10.  94 

2.  45 
6.62 

3.  32 

0  95 

Silica  (soluble  in  solution  of  Na,('():i)  

Silica  (insoluble  in  solution  of  Xa^C03)  

Feme  ozid  <  l-'e-.o^) 

Calcium  oxid  (CaO) 

Magnesium  oxid  (MgO) 

Sodium  oxid  (Xa,(  )> 

14  70 

Phosphoric  acid  I P,Os) 

"   45 

1.71 

Carbonic  acid  (CO*) 

9.  L5         9.12 
2.76   •     2.75 

2  51 

Chlorin  (CI)    

1   41 

Total 

Oxygen  equivalent  t<>  chlorin 

101.07      101.10 
0.62        0.62 

101.08 
0.62 

100.32 
0.31 

100.  53 
0.31 

100.42 
0.31 

100.45      11)0.48 

100.46 

100.01 

100.  22 

100  11 

From  the  above  numbers  it  is  seen  that  the  ash  of  the  peeled  root  is 
especially  rich  in  potash,  almost  one-half  of  the  total  weight  being  com- 
posed of  this  substance.  The  potash  is  combined  chiefly  with  carbonic 
and  phosphoric  acids.  In  the  ash  of  the  bark,  as  might  be  expected, 
silica  is  the  predominant  element,  more  than  half  the  total  weight  cou- 
sisting  of  this  substance. 

Assuming  a  yield  of  5  tons  of  roots  per  acre,  the  weights  of  the 
important  fertilizing  materials  removed  by  such  a  crop  can  be  readily 
calculated  from  the  data  given. 

Since  the  bark  forms  approximately  2.2  per  cent  of  the  entire  root, 
tin-  total  crop  would  be  made  up  of  the  following  amounts  of  bark  and 
peeled  root  which  would  contain  the  amounts  of  mineral  matter  given 
below: 


Pounds. 

Pounds 

<>l   a>h. 

9,780 

•_'■_•»  i 

!'.'   -> 

1    II 

. 

10,  000  <           54.  32 

The  more  important  mineral  matters  contained  therein  are 


Lime  (CaO)  , 

MgO)    

C .i.i-l,  i  K  ,'i, 

Pbospborl.  ;..  ld(PfO») 

■i  in- 


Ash  tVmu         .     -    , 

■"">• 


Pound*. 

5.31 

•JO.  77 
7.77 


L2. 56 


Pounds. 
0  29 

.  16 

.  11 


:!.•_'» 


i  otal  ash 

rom  5  tun* 

pounds). 

Pounds. 

5.  m 

21    12 


16  60 


13 


The  less  valuable  mineral  plant  foods,  that  is,  those  that  are  of  so  lit- 
tle note  as  to  require  no  conservation  or  addition,  amount  to  15.60 
pounds  per  acre  and  the  more  valuable  to  32.72  pounds  per  acre. 

Quite  a  number  of  preparations  was  made  from  the  starch  of  the  root, 
and  anion*;-  them  may  be  mentioned:  First,  tapioca 5  the  first  portions 
of  starch  washed  out,  especially,  produce  an  excellent  article  of  tapioca 
when  treated  in  the  usual  way.  Second,  glucose:  both  the  fresh  root 
and  the  extracted  root  yield  full  theoretical  amounts  of  glucose,  and 
samples  of  this  article  were  made  by  the  conversion  of  the  starch  both 
by  sulphuric  acid  and  diastase.  The  samples  of  glucose  made  from  the 
starch  were  exceptionally  good,  especially  when  diastase  was  used, 
the  glucose  in  this  case  containing  large  quantities  of  maltose.  Com- 
mercially it  would  be  more  profitable  to  make  the  glucose  directly  from 
the  fresh  root,  in  which  case  the  considerable  percentage  of  cane  sugar 
contained  by  it  would  be  saved,  whereas  if  glucose  be  made  from  the 
starch  the  cane  sugar  is  previously  washed  out.  On  account  of  the 
presence  of  the  bark,  however,  the  glucose  made  from  the  whole  root 
is  not  so  fine  in  quality  as  that  made  from  the  pure  starch.  Third, 
alcohol;  the  glucose  on  fermentation  affords  the  usual  quantity" of 
alcohol.  Fourth,  cane  sugar;  a  beautiful  preparation  of  cane  sugar 
was  made  from  the  water  used  in  washing  out  the  starch.  The  amount 
of  cane  sugar,  however,  is  not  large  enough  to  warrant  its  extraction 
on  a  commercial  scale  from  the  waters  used  for  washing.  It  is,  how- 
ever, present  in  sufficient  quantity  to  indi- 
cate that  in  making  glucose  it  is  better  to 
use  the  whole  root  as  indicated  above. 

The  general  result  of  the  analytical 
work  is  SUCh  as  to  establish  the    fact  that 

the  cassava  is  a  plant  of  high  economic 

value  and  worthy  of  the  attention  of  those 
interested  in  the  carbohydrate  products 
of  the  country. 

METHODS   OF   CULTURE. 

Cassava  has  been  grown  for  one  year 
on  the  Department  Experiment  Station 
at  Kunnymede  (post  office,    Narcoossee  . 

Osceola  County.  Ida.  The  crop  was 
grown  as  food  for  stock.  The  field  in 
which  the  crop  was  grown  is  high  pine 
sand,  with  almost  no  other  ingredient. 
The  illustration  of  the  cassava  given  here 

with     is    from    a    photograph    of  a     plant 

taken  from  afield  Dear  the  station.    The  11..1. 

soil  on  which  it  was  grown  was  apparent  ly  pure  sand.      It  represents  the 

larger  plants  in  the  field,  bul  not  by  any  means  the  largest    The  illus- 
tration (fig.  L)  shows  in  a  striking  manner  the  stem  and  root  develop 


14 

ment.    This  plant,  of  which  the  photograph  is  given,  was  5  feet  high. 

The  roots  in  the  soil  occupy  a  more  nearly  horizontal  position  than  is 
shown  in  the  figure.  The  thickened  part  of  the  stem  to  which  the  roots 
are  attached,  represents  the  catting  from  which  the  plant  grew. 

Attempts  were  also  made  to  grow  the  cassava  in  a  piece  of  very  wet 
muck  land  on  the  station  in  which  sugar  cane  would  not  grow  to  any 
advantage.  An  immense  development  of  .tops  was  secured,  some  of  the 
plants  reaching  a  height  of  10  feet  and  resembling  young  trees.  The 
root  development  was  fair,  but  not  commensurately  increased  with  the 
top  growth.  Some  of  the  Btems  were  easily  2  inches  in  diameter.  On 
well-drained  muck  land  I  think  the  crop  would  be  large  and  profitable. 

In  sand  land  the  planting  should  be  preceded  by  the  removal  of 
stamps,  sproats,  etc.,  and  the  soil  given  a  thorough  plowing.  Lt  is 
advisable  to  spread  about  300  pounds  of  line  raw  Florida  phosphate 
floats  or  about  150  pounds  of  superphosphate  containing  11*  percent 
available  acid,  to  the  acre.  This  may  be  applied  as  ;i  top  dressing  and 
thoroughly  worked  into  the  soil  by  a  deep-running  cultivator.  The 
rows  should  be  marked  out  in  furrows  3  to  4  inches  deep  and  from  3  J 
to  4  feet  apart.  To  get  a  good  stand  about  double  the  number  of  cut- 
tings required  to  produce  2,500  hills  per  acre  should  be  planted.  The 
excess  of  plants  can  be  removed  by  a  hoe  as  soon  as  vigorous  growth  is 
assured,  leaving  one  hill  each  3  or  4  feet.  About  150  pounds  of  kainit 
per  acre  should  be  dropped  in  the  hills  before  planting,  together  with 
an  equal  amount  of  cotton-seed  meal,  or  half  that  amount  of  Chile  salt- 
peter |  nitrate  of  soda). 

The  cultivation  should  be  such  as  to  keep  the  field  free  of  all  weeds 
and  the  surface  of  the  soil  well  stirred.  While  the  plants  arc  young 
deep  Cultivation  is  not  objectionable,  but  as  soon  as  the  root  system 
begins  to  develop,  flat  superficial  culture  must  be  practiced;  not  to 
exceed  2  indies  in  depth.  Some  cultivators  draw  the  soil  to  the  plant 
(luring  cultivation  so  as  to  form  a  ridge  at  the  time  of  laying  by.  Where 
nitrate  of  soda  has  been  u^<\  an  additional  50  or  75  pounds  per  acre 
Should  be  sown  broadcast  just  before  the  final  cultivation.  The  above 
method  is  the  one  which  should  be  followed  for  the  poorest  kind  of  sand 

soil-,  where  a  maximum  crop    is  desired.      For   muck  soils,  the  cotton 
seed  meal  and  nitrate  of  soda  should  be  omitted  and  about  500  pounds 

of  Florida  phosphate  floats  wst^i  per  acre.  If  sand  soils  are  covered  with 
;i  good  layer  of  muck  before  the  plowing  the  nitrogenous  fertilizers 
may  also  be  omitted  or  reduced  in  quantity. 

In  ordinary  seasons  with  the  treatment  outlined  above,  a  crop  of 

from  1  to  7  tons  per  acre  will  be  secured.  On  sand  soils  containing  a 
little  organic  matter  approaching  the  hammock  variety,  a  fair  yield  of 

from    _Mo   1  tons  pei-   acre  will    he   secured    by  good    cultivation  without 

fertilizing. 

For  seed,  the  stems  of  the  unfrosted  plants  are  cut  into  pieces  about 
6  inches  in  length,  care  being  taken  that  each  piece  has  two  or  more 
eyes,     in  planting,  these  pieces  may  be  laid  directly  down  in  the  fur 


But.  44,  Div.  Chemistry,  U.  S.  Dept.  Agriculture. 


Fio  1 


Cassava  Starch  x  iso. 

PLAIN     ILLUMINATION. 


Kio2 


g; 


©Co  ©      ^   o    ■' 


Corn  Starch  x  iso 

plain  illumination. 


Plate  I 


Bul.  44,  Div.  Chemistry,  U.  S.  Dept.  Agriculture. 


Plate  2. 


Fio  1 


Cassava  Starch  x  iso. 

polarized  light. 


F1&2 


Corn  Starch  x  iso 

POLARlZrO    LIGHT 


15 

rows  and  covered,  but  the  general  practice  is  to  place  them  obliquely 
in  the  furrows  so  that  one  end  may  not  be  covered.  In  case  of  a  threat- 
ening frost  before  a  field  is  ready  for  planting  the  unfrosted  tops  may 
be  cut,  thrown  into  heaps,  and  protected  with  leaves  or  trash  from  the 
action  of  the  frost.  They  should,  however,  be  embedded  in  moderately 
moist  earth  if  they  are  to  be  kept  before  planting  for  any  length  of 
time.  In  case  of  frost  before  the  seed  is  saved  the  stumps,  i.  e.,  the 
points  of  union  of  the  top  with  the  root,  will  usually  be  found  unin- 
jured, and  these  may  be  cut  away  and  planted  instead  of  the  cuttings 
just  described.  The  larger  parts  of  the  stems  immediately  above  the 
ground  make  the  best  seed. 

The  roots  should  be  left  in  the  ground  until  they  are  needed  for  use, 
whether  for  food,  for  starch,  or  for  glucose.  The  crop  can  be  harvested 
at  any  time  during  the  year,  but  the  best  season  is  from  October  to 
M ay.  The  roots  should  not  be  allowed  to  grow  more  than  two  seasons. 
and  for  most  purposes  it  is  believed  that  an  annual  harvest  will  prove 
the  more  profitable. 

As  is  the  case  with  all  new  and  promising  plants,  the  most  extrava- 
gant statements  have  been  made  in  regard  to  tin1  amount  of  cassava 
which  can  be  produced  per  acre.  In  many  of  the  returns  received 
from  our  correspondents  in  Florida,  statements  were  made  in  regard  to 
the  yield  which  were  entirely  beyond  the  bounds  of  reason.  These 
extravagant  statements,  of  course,  did  not  proceed  from  any  desire  on 
the  part  of  correspondents  to  misstate  the  facts,  but  on  account  of 
their  misapprehension  of  them.  Statements  of  yield  are  made  as  a  rule 
not  upon  accurately  measured  and  weighed  products,  but  upon  a  mere 
glance  over  a  field  or  the  taking  of  a  few  hills.  It  is  easy,  therefore,  for 
the  most  honest  and  upright  correspondent  to  fall  into  gross  error  in 
regard  to  the  amount  which  will  be  furnished  by  an  acre.  In  my  own 
observation  of  small  areas  ami  from  the  accredited  statements  of  those 
authorities  which  seem  to  merit  the  highest  consideration,  I  am  con- 
vinced that  on  the  ordinary  pine  land  of  Florida,  with  proper  prepara- 
tion and  cultivation  and  appropriate  fertilization,  a  yield  of  from  1  to  7 
or  perhaps  8  tons  per  acre  may  be  reasonably  expected.  It  is  difficult 
to  see,  however,  how  it  is  possible  for  such  yields  as  have  been  reported, 
viz,  40,  50,  and  even  <)0  tons  per  acre,  to  he  gathered.  In  exceptional 
conditions,  as  in  the  case  with  all  crops,  exceptional  yields  ma\  be 
obtained,  but  these  must  not  be  considered  in  the  practical  study  of 
the  problem  of  profitable  production. 

The  profit  which  the  farmer  may  make  from  growing  this  crop,  and 
the  manufacturer  from  using  it,  should,  in  my  opinion,  he  based  upon 
a  yield  of  4  or  5  tons  per  acre.      If  it  be  desired  to  make  starch  from  the 

plant,  we  may  suppose  as  a  minimum  rate  of  yield  that  30'peroentof 
the  weigh!  of  the  fresh  root  may  be  obtained  as  merchantable  starch  of 

a  high  grade.  On  a  yield  of  4  tons  per  acre  this  would  amount  to 
eight  tenths  of  a  ton.  or  L,600  pounds.  Compare  this  wit  It  the  weight 
of  starch  obtained   from   Indian  corn  producing  i<>  bushels  per 


16 


UNIVERSITY  OF  FLORIDA 

1 1  miii  ii  inn 

3  1262  09216  6700 


The  yield  of  merchantable  starch  of  a  high  grade  may  be  placed  at  35 
pounds  per  bushel,  which,  for  40  bushels  would  amount  to  1,400  pounds. 
It  is  thus  seen  that  the  rate  of  yield  per  acre  in  the  matter  of  starch 
from  cassava  would  be  fully  equal  if  not  superior  to  that  from  Indian 
corn. 

If  the  matter  of  the  manufacture  of  glucose  be  considered  the  esti- 
mate is  even  more  favorable.  Our  experiments  have  shown  that  after 
the  removal  of  the  bark  the  whole  root  may  be  rasped  and  treated 
directly  for  the  manufacture  of  glucose,  either  by  inversion  with  dias- 
tase or  by  treating  with  dilute  sulphuric  acid.  In  the  latter  case  not 
only  were  the  starch  and  sugar  present  in  the  root  obtained  as  glucose, 
l)i it  also  a  considerable  quantity  of  the  digestible  liber.  It  is  not  an 
extravagant  statement,  therefore,  to  suppose  that  fully  30  per  cent,  on 
the  weight  of  the  fresh  root,  could  be  obtained  as  commercial  glucose. 
This  would  give  a  yield  per  acre  of  L.2  tons,  or  2,400  pounds.  These 
statements  are  made,  of  course,  subject  to  the  practical  determinations 
of  the  manufacturer  of  glucose  and  starch  from  this  plant  Attempts 
have  already  been  made  in  the  manufacture  of  starch,  but  of  course 
the  full  development  of  this  industry  must  await  the  investment 
of  capital  and  the  necessary  adjustment  of  new  machinery  to  new 
processes. 

The  object  of  the  present  bulletin  is  simply  to  point  out  the  possi- 
bilities  of  the  culture  of  cassava,  not  only  for  the  farmer  of  Florida  but 
also  for  the  manufacturer  and  merchant. 

In  its  preparation  Mr.  E.  E.  Ewell  has  conducted  the  chemical  and 
preparatory  work  and  Mr.  (r.  L.  Spencer  has  taken  the  photographs. 

CONCLUSIONS. 

(1)  ( lassava  can  be  cultivated  with  safety  and  profit  in  the  greater 
part  of  tin'  peninsula  of  Florida,  and  probably  also  in  southern  Ala- 
bama, Mississippi,  Louisiana,  and  Texas. 

(2)  It  will  yield  with  fair  treatment  on  the  sand  soils  from  I  too 
tons  per  acre. 

(3)  It  will  give,  when  properly  manufactured,  from  20  t<>  l'o  per  cent 
of  the  weighi  of  tin-  fresh  root  in  Btarch  of  high  grade. 

(4)  The  starch  is  naturally  in  a  pure  state  and  no  chemicals  of  any 
kind  are  necessary  in  its  manufacture. 

(5)  The  Starch    resembles   in    its    physical     properties    the    starch  of 

maize  and  can  be  n-ed  as  a  substitute  therefor  in  all  cases, 

(<»)  An  excellent  article  <>('  tapioca  can    be  prepared    from  the  starch 

of    the  ca>s;i\  ;i    plant. 

Glucose  can  be  prepared  directly  from  the  Btarch  <>r  more  profit 

ably  from  t  &C  |>nl|>  of  the  peeled  root. 

(8)  The  plant    furnishes   an    excellent    human    and   cattle   food,  deli 

dent,  however,  iii  nitrogen.     It  would  make  a  well  balanced  ration  for 
cattle  when  mixed  with  one  fourth  its  weight  of  cotton  seed  ml  cake. 


